Ender 3 Dual Z Screw Crash Leveler

After I added a second z-axis screw and saw that my x-axis gantry was skewed I tried several variants of crash levelers. I would prefer to crash at the bottom since there are fewer variables that effect the level that you get on the x gantry. However, that means that you have to physically remove the levelers since they have to be above bed height. I considered some kind of electro-mechanical device that would automate the process but hanging the leveler from the top of the frame is so much simpler. I do like the original design and I used it for a while. I have few problems with it: 1. it is actually leveling the brackets that the x-gantry is attached to. Its not a big deal but that does introduce more error. So, I made this leveler to reach over the bracket and land directly on the x-gantry to ensure that it is level to the top of the frame (or the placement of the levelers). 2. Aesthetically I hated the way my printer looked with two big ears on either side of the frame. 3. I didn't see the need to span the entire width of the frame so when I made these I saved some plastic. It is plenty rigid. 4. The cable management of my extruder guides the wires up and I have a direct drive extruder so I can never go all the way to the top. Therefore, I made this a little longer for my setup. Placing these flush with the top of the frame I level out at Z= 203 . 

I do use G34:

Z_MAX_POS 203

GANTRY_CALIBRATION_EXTRA_HEIGHT  5. 

You have to make sure that after moving the gantry to the top and leveling it that you move  it back down enough so that the extruder doesn't hit the leveler when it homes X. Since the Marlin default is to do a G28 after the G34 is complete you have to add extra G code to do this:

Configuration_adv.h

#define GANTRY_CALIBRATION_COMMANDS_POST  "G1 F200 Z150\nG28"

I move Z to 150 with a feed-rate of 200, then I do G28.

I have mine mounted at the top but I don't see any reason that they could not also be used at the bottom and then removed. 

Two are required :) and I used M4 bolts and T-nuts to secure them

I used PETG:

0.2mm layer height

3 walls, 4 top and bottom layers, 20% infill

I printed it on the side and used supports everywhere.

I cut the original down to ½ the width and I added a leg and a foot.